Fix nightly (#5413)

### What this PR does / why we need it?
This pacth mainly do the following things:
1. Bugfix for multi_node_tests log, log names must be unique when
uploading logs.
2. Optimize `get_cluster_ips` logic, increase the max retry times for
robustness
3. Abandoned the existing gh-proxy temporarily until it is stable
enough.
### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

- vLLM version: release/v0.13.0
- vLLM main:
81786c8774

---------

Signed-off-by: wangli <wangli858794774@gmail.com>

.github/workflows/_e2e_nightly_multi_node.yaml

@@ -288,7 +288,7 @@ jobs:
           if: always()
           uses: actions/upload-artifact@v4
           with:
-            name: pod-logs
+            name: ${{ inputs.config_file_path }}-pod-logs
             path: /tmp/vllm*_logs.txt
             retention-days: 7
 

.github/workflows/nightly_test_a3.yaml

@@ -62,10 +62,6 @@ jobs:
           - name: multi-node-qwenw8a8-2node
             config_file_path: Qwen3-235B-W8A8.yaml
             size: 2
-          # TODO: Replace deepseek3.2-exp with deepseek3.2 after nightly tests pass
-          # - name: multi-node-dpsk3.2-exp-2node
-          #   config_file_path: DeepSeek-V3_2-Exp-bf16.yaml
-          #   size: 2
           - name: multi-node-deepseek-r1-w8a8-eplb
             config_file_path: DeepSeek-R1-W8A8-EPLB.yaml
             size: 4